The last thing Chelsea can afford here in this UEFA Champions League group stage game in Romania on Tuesday is a loss, but the same exact thing can be said about hosts Steaua Bucharest.

Both clubs were defeated in their Group E openers two weeks ago, and a loss here for either side would put them so far behind the pack that nothing short of near-perfection would be necessary in their remaining four matches to try to find a way to advance to the knockout stage.

These two teams—who both play in their respective country’s capitals—are somewhat familiar with each other having met in the round of 16 of the UEFA Europa League this past March, with both sides holding serve on their home turf.

Chelsea would eventually go on to win the tournament, defeating Benfica, 2-1 in the final on May 15 in Amsterdam.

When these two met in the Romanian capital of Bucharest on March 7, Steaua and goalkeeper CiprianTatarusanu shut out the Blues in a very impressive performance by the home team and an extremely lackluster one by the boys from West London, who were defeated 1-0.

But the English Premier League representatives did roll to a 3-1 win on the return leg a week later at Stamford Bridge thanks to goals by John Terry, Juan Mata and Fernando Torres to narrowly win the tie on aggregate (3-2).

With a surprise home loss to FC Basel in the tournament still fresh on their minds heading into this one, expect the Blues to be on their best behavior for all 90 minutes against the upstart Roș-Albaștrii.

Steaua (6-1-0) currently sits in first place in the Liga I Bergenbier table and has scored 19 goals and allowed just five so far in Romania’s top flight of football behind coach LaurențiuReghecampf.

Both goal scorers for the Roș-Albaștrii against Chelsea last year—Raul Rusescu (Sevilla) and Vlad Chiriches (Tottenham Hotspur)—are no longer with the club but Sampdoria-loanee Federico Piovaccari (four goals) has been a pleasant surprise at forward so far for Steaua.

Adrian Popa (three goals), Leandro Tatu, Adrian Cristea and NicolaeStanciu also feature in the Steaua attack while ŁukaszSzukala, IasminLatovlevici and Florin Gardoş help hold down the defense in front of dependable goalkeeper Tatsrusanu.

Due to injuries, Steaua will be without center-forward Stefan Nikolic (knee) and winger AlexandruChipciu for the game.

Steaua lost its Group E opener to FC Schalke 3-0 in Germany and has not been great against teams from England in European play (5-4-6) but much improved (5-2-1) against them when playing in Bucharest.

Chelsea (3-2-1) sits in fourth place in the Premier League table and is coming off a hard-fought 1-1 draw against Spurs at White Hart Lane on Saturday. After late goals from Mohamed Salah and Marco Streller handed the Blues a loss in their opening group game, the pressure is on for them to improve their qualification chances.

The big news coming out of the Blues camp for this game is that playmaking midfielder Mata will be indeed getting the start after his performance after coming on for the second half against Spurs in the past weekend’s London derby and playing quite admirably.

This is the way players have to tell me they want to be in my team. I sometimes make a mistake as a manager, but I make my decisions on what I see in training and on the pitch. I liked what Mata did against Swindon in the Capital One Cup and I put him on the bench today.

Now I like what I see when he plays for 45 minutes. I’m a very happy manager when I see Juan Mata playing like this. I can tell you now that he will play against Steaua Bucharest in the Champions League on Tuesday—he deserves that chance. I want my players to tell me they want to play. Juan told me that.

So it seems that maybe Mourinho’s stubborn side is prepared to give in to the fact that the club’s two-time Player of the Year might actually deserve a spot in a starting XI which has painfully shown to have a bit of a problem scoring goals this calendar year.

And with the way he’s handled the Mata situation, maybe Chelsea fans now know just a little bit how Real Madrid fans might have felt at times last season under the leadership of the self-anointed Special One.

Anyway, who starts around Mata is anyone’s guess, but with a win being so important in this one, there’s no doubt Petr Cech will be the Blues goalkeeper against Steaua. And Samuel Eto’o may get the nod at striker after Torres’ red card in North London just three days earlier.

One guy who definitely won’t be part of the plan for Chelsea is midfielder Marco van Ginkel, who is out for six months after having surgery last week to repair a cruciate knee ligament injury.

Chelsea heads into this match ranked a deceptive No. 4 in the latest UEFA club rankings with Steaua checking in at No. 54, but this disparity is quite deceiving, and the Romanians are just as desperate as the Blues and have already proven in 2013 that they can beat this team in this city.

Who knows where the Blues will sit in the group standings when these two clubs meet for the return leg at Stamford Bridge on Dec. 11, but a loss or even a draw here would surely light a fire under the critics again and hamstring Chelsea for the duration of group play.

The Blues' next game is Oct. 6 (Sunday) when they travel to Carrow Road to face 15th-place Norwich City (2-1-3) in Premier League play (NBC Sports Network Live Extra, 8:30 a.m. ET/5:30 a.m. PT).